Triple Chocolate Layer Cake with Marshmallow Frosting

Chocolate cake gets an exciting makeover with three distinct chocolate flavours hidden beneath luscious vanilla marshmallow fluff buttercream in this recipe for triple chocolate layer cake. It's a simple but effective concept.

This recipe was first published in March 2016 and updated in May 2020.

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March is my crazy month of birthday cake baking. My record is 4 cakes in the space of just 10 days. That’s a lot of eggs. A lot of icing. A lot of cake. It really is a cake-a-thon. In the midst of this baking madness, this fantastic triple chocolate layer cake with marshmallow buttercream was born for my younger daughter’s birthday a few years back.

We’re talking about three distinct layers of light & bouncy chocolate sponge cake:

• White chocolate & vanilla – sweet & fresh
• Malted milk chocolate - homely, comforting chocolate heaven
• Dark Chocolate – satisfyingly intense

What's not to love about this triple chocolate layer cake?

What Makes This Chocolate Cake So Special?

Yes, this triple chocolate layer cake is essentially a large chocolate cake. But the different layers that reveal themselves once the cake is cut into takes it over the edge. It is far more exciting than a typical chocolate cake.

I'd say this recipe for triple chocolate cake is ideal for any chocolate lover - child or adult. It was a hit with everybody around our tea-table.

One or two people picked out their favourite layers, but most, me included, just fell for the entire bundle.

Then of, course, there's the marshmallow fluff buttercream.

What is Marshmallow Fluff Buttercream?

It's a regular buttercream with the addition of Marshmallow Fluff & vanilla bean paste.

Marshmallow Fluff, if you've not come across it before, is a spreadable marshmallow creme, hugely popular in the US. It is now commonly available in UK supermarkets too - try looking for it in the chocolate spread area.

This marshmallow fluff buttercream is my absolute favourite – you may remember it from my Pumpkin Pie Whoopie Pies. It is everything you could wish for in an icing: sweet, light, fluffy, easy to spread and, without a doubt, a step up from standard vanilla buttercream.

And this marshmallow frosting makes a welcome deviation from the cocoa theme in this decadent recipe for triple chocolate cake.

How do you Make This Cake?

There are three stages to making this fantastic recipe:

• Baking the sponge cakes
• Making the buttercream
• Assembling and decorating the layers

Before we get to the instructions, I'd like to talk about working with melted chocolate. It can be a tricky beast to master.

How to successfully Mix Melted Chocolate into Cake Batter

Each layer of this extravagant triple chocolate cake contains real chocolate. When melted chocolate is added to cake batter, it can have a tendency to cool too quickly and end up seizing before it is fully mixed in.

Occasionally readers write in to tell me that although they enjoyed the cake, they experienced this problem. So I'd like to share a few tips to help you avoid this issue too:

• Use room temperature ingredients - melted chocolate will start to reset if it comes into contact with other colder ingredients, so never use chilled ingredients for this recipe. This is perhaps the main reason chocolate seizes when mixed into cake batter
• Work quickly - chocolate that has cooled too much after melting is the second most likely reason that the chocolate does not mix smoothly into the cake batter, so if you are a slower baker, keep this in mind. I'm a relatively quick baker, so I melt the chocolate before I begin to mix the cake batter. This is so that it can cool for around 5 minutes
• Stir a tablespoon of cake batter directly into the chocolate and then blend it all back into the remaining cake batter. This step really does help reduce the risk of the chocolate seizing when incorporating it into the cake batter since it helps even-out the differences in temperature between the chocolate and the cake batter

Keep these 3 points in mind as you make this recipe for triple chocolate cake and you'll be rewarded with 3 perfectly blended batters.

Making the Cakes

Now we've covered the basics of working with chocolate in cake batter, follow these instructions to make this fantastic recipe for triple chocolate layer cake:

• Grease and line 3 x 6-inch circular baking tins and preheat the oven
• Melt the 3 types of chocolate in separate bowls. Set aside
• Now remember to work quickly
• In a bowl beat the butter and sugar until light and fluffy, using electric beaters. Add the eggs, one at a time, beating well between each addition
• Add 3 tablespoon of milk and beat again. Sift the flour and baking powder into the bowl and mix well
• Divide the cake batter equally into 3 small mixing bowls - you can weigh it out for precise division if desired
• For the White Chocolate & Vanilla Sponge:
  • Take one of the 3 bowls of the cake batter
  • From this bowl, take a tablespoon of the cake batter and quickly mix it into the melted white chocolate
  • Gently fold this white chocolate mixture and the vanilla extract back into the bowl containing the rest of the cake batter - remember, this double-action will stop the chocolate from seizing when it is mixed into the cake batter
  • Spoon the batter into one of the baking tins and spread it out with a blunt knife
• For the Malted Milk Chocolate Sponge:
  • stir an extra tablespoon of milk and the Ovaltine powder into the second bowl of cake batter
  • From this bowl, take a tablespoon of the cake batter and stir it quickly into the melted milk chocolate
  • Fold this chocolate mixture back into the rest of the cake batter then spoon the batter into another of the baking tins & spread it out
• For the Dark Chocolate Sponge:
  • stir an extra tablespoon of milk and the cocoa powder (sifted) into the remaining bowl of cake batter
  • Quickly mix a tablespoon of this cake batter into the melted dark chocolate
  • Fold this chocolate mixture back into the rest of the cake batter, spread the batter into the last of the baking tins
• Bake all three cakes for 20-25 minutes until the cake springs back when lightly pressed or a skewer comes out clean. Let cool completely on a baking rack

See the recipe card for full instructions.

Please note: the recipe listed is for a three-layer chocolate cake made in 6-inch cake pans. This cake is ideal for serving 8-10 people.

These cake pans are smaller than typical ones, which tend to measure 8-inches. I have included some instructions in my recipe notes for scaling up to large pans. 

Make the Marshmallow Fluff Buttercream

These is absolutely nothing complicated in making this buttercream. Simply beat the icing sugar, butter & vanilla paste together until smooth, follwed by the cream cheese. Finally, mix in the marshmallow fluff.

Since this buttercream contains cream cheese, it does need to be refrigerated if it will not be consumed in a few hours.

Either make it in advance, chill and allow to come back to room temperature before using it or use to decorate the cake and refrigerate, again remembering to let it come to room temperature before serving.

Assembling the Cake

Spread a heaped tablespoon of frosting over the white chocolate cake layer, smooth with a blunt knife and top with the malted milk chocolate layer. Repeat to add the final layer of dark chocolate cake.

Once the final layer of cake has been added, carefully spread a thin layer of icing all over the top and sides of the cake - a palette knife is good for this. I find that coating the cake in a thin layer all over helps to seal in the crumbs, especially if you can chill the cake for 20 minutes or so at this point too.

Use the remaining icing to create a thicker layer that covers the cake entirely, then carefully move your cake onto a serving plate and touch up the icing if necessary.

Once you are satisfied, you can add a pattern if you want to. I used the back of a dessert spoon to lift the icing in places to give a rugged appearance.

Decorate with crushed or chopped chocolate if desired.

I knew I was onto a winner for my girl with this recipe for triple chocolate cake. She adores chocolate & marshmallows so to have a multitude of chocolate all stacked up into a birthday cake and then include marshmallow in the icing was like a dream come true for her.

And me, let's be honest.

Have you seen my other triple layer cakes?

• Chocolate & Vanilla Malted Milkshake Cake with Italian Buttercream
• Triple Layer Coffee Cake
• Cinnamon Apple Cake with Salted Maple Buttercream
• Turkish Delight Cake

Have you made these sugared doughnuts? Please give it a rating or leave a comment - I love to hear how you get along with my creations.

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Triple Chocolate Layer Cake

Jane Saunders

Chocolate cake gets an exciting makeover with three distinct chocolate flavours hidden beneath luscious vanilla marshmallow buttercream. Simple but effective.

5 from 18 votes

Print Pin Rate

Course: Baking, Cake, Dessert

Cuisine: World

Prep Time: 45 minutes

Cook Time: 30 minutes

Total Time: 1 hour 15 minutes

Servings: 10 Slices

Calories: 654kcal

Equipment

• ▢
  Please note: this recipe uses 3 x 6-inch circular cake tins. If you are using standard 8.5 inch tins please see my notes below.

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Ingredients

For the Cakes

• ▢ 180 g/ 6 ½oz softened butter
• ▢ 180 g/ 6 ½oz caster sugar
• ▢ 3 eggs
• ▢ 5 tablespoon milk
• ▢ 180 g/ 6 ½oz plain (all purpose) flour (sifted)
• ▢ 2 teaspoon baking powder
• ▢ 50 g/ 2oz white chocolate - finely chopped
• ▢ 50 g/ 2oz milk chocolate - finely chopped
• ▢ 50 g/ 2oz dark chocolate - finely chopped
• ▢ ½ teaspoon vanilla extract
• ▢ 1 ½ tablespoon Ovaltine (chocolate malt powder)
• ▢ 1 ½ tablespoon cocoa powder

For the buttercream

• ▢ 125 g/ 4 ½oz softened butter
• ▢ 250 g/ 9oz icing (confectioner's) sugar
• ▢ 125 g/ 4 ½oz cream cheese
• ▢ 1 teaspoon vanilla bean paste
• ▢ 150 g vanilla Marshmallow Fluff

Decoration - 1 Cadbury's flake (or 40g chopped/ grated milk chocolate)

Instructions

Bake the cakes

• Preheat the oven 170°/ 325°F/ GM3
• Grease and line 3 x 6-inch circular baking tins (note these are smaller than average tins - if you are using 8-inch tins see my notes on how to scale up the recipe)
• Melt the 3 types of chocolate in separate bowls. Set aside
• In a bowl beat the butter and sugar until light and fluffy, using electric beaters. Add the eggs, one at a time, beating well between each addition
• Add 3 tablespoon of milk and beat again. Sift the flour and baking powder into the bowl and mix well
• Divide the cake batter equally into 3 small mixing bowls
• For the White Chocolate & Vanilla Sponge: from the first mixing bowl take a tablespoon of the cake batter and stir it quickly into the melted white chocolate. Then gently fold this white chocolate mixture and the vanilla extract back into the bowl containing the rest of the cake batter. This double-action will stop the chocolate from seizing when it is mixed into the cake batter. Gently spoon the batter into one of the baking tins and spread it out with a blunt knife
• For the Malted Milk Chocolate Sponge: stir an extra tablespoon of milk and the Ovaltine powder into the second bowl of cake batter. From this bowl, take a tablespoon of the cake batter and stir it quickly into the melted milk chocolate. Then fold this chocolate mixture back into the rest of the cake batter. Spoon the batter into another of the baking tins & spread it out
• For the Dark Chocolate Sponge: stir an extra tablespoon of milk and the cocoa powder (sifted) into the remaining bowl of cake batter. Quickly mix a tablespoon of this cake batter into the melted dark chocolate, then fold this chocolate mixture back into the rest of the cake batter. Spread the batter into the last of the baking tins
• Bake all three cakes for 20-25 minutes until the cake springs back when lightly pressed or a skewer comes out clean
• Let cool in the tins for 2 minutes, then remove from the tins, peal off the baking parchment from the bottom of each sponge cake and let cool completely on a wire rack

Make the Marshmallow buttercream

• Put the icing sugar, butter & vanilla paste into a large bowl and beat until smooth
• Beat in the cream cheese until smooth, then mix in the marshmallow fluff

Assemble the cake

• Lay the white chocolate sponge cake onto a board and spread a heaped tablespoon of the icing on top, then place the malted milk chocolate cake carefully on top of the layer of icing
• Top with another spoonful of icing, spread it out and add the dark chocolate layer of cake
• Once the final layer of cake has been added, carefully spread a thin layer of icing all over the top and sides of the cake - a palette knife is good for this. I find that coating the cake in a thin layer all over helps to seal in the crumbs. Once you have done this, use the remaining icing to create a thicker layer that covers the cake entirely.
• Carefully move your cake onto a serving plate and touch up the icing if necessary. Once you are satisfied, you can add a pattern if you want to. I used the back of a dessert spoon to lift the icing in places to give a rugged appearance
• Decorate with crushed or chopped chocolate if desired

Notes

This recipe uses 3 x 6 inch circular cake tins. If you wish to use standard 8.5 inch tins, my suggestion is to simply double the recipe. In an ideal world, you would scale up the recipe to bake it using 5 eggs, but that leads to some fiddly measurements. Making double is far easier - just ensure you do not fill your sandwich tins more than ⅔ full with the batter and use the leftover batter to make a few cupcakes. You perhaps will not need to double the buttercream though - I'd suggest making 1.5 times that stated in the recipe.

Nutrition Per Serving (Approximate)

Calories:654kcal | Carbohydrates:81g | Protein:6g | Fat:36g | Saturated Fat:22g | Cholesterol:130mg | Sodium:289mg | Potassium:247mg | Fiber:2g | Sugar:60g | Vitamin A:1014IU | Vitamin C:1mg | Calcium:101mg | Iron:2mg

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